IOptions vs IOptionsSnapshot vs IOptionsMonitor in .NET Core

In.NET Core, IOptions, IOptionsSnapshot, and IOptionsMonitor are used to access configuration values. Here’s a brief comparison:

• IOptions: This is the simplest way to access configuration values. It’s typically used when the configuration values do not change while the application is running.

• IOptionsSnapshot: This is a scoped service and provides a snapshot of the options at the time the IOptionsSnapshot<T> object is constructed. It has a scoped lifetime to guarantee you have the same configuration values during a single request. It could be odd behavior if the content changes in the mid-request.

• IOptionsMonitor: This is a singleton service that retrieves current option values at any time, which is especially useful in singleton dependencies. It is registered in the DI container as a singleton and is capable of detecting changes through the OnChange event subscription. It has a CurrentValue property. It’s more commonly used in singleton services such as hosted services because IOptionsSnapshot cannot be used to refresh data.

In summary, you would use IOptions if your configuration doesn’t change, IOptionsSnapshot if you want to ensure consistent configuration values during a request, and IOptionsMonitor if you need to access updated configuration values in singleton services.